(Revelation 1:8)"I am the Alpha and the Omega, says the Lord God, who is and who was and who is to come, the Almighty." (ESV)
Alpha and Omega are the first and last letters of the Greek alphabet. Jesus is referred to as the Lord God, the Almighty. Christ is divine, eternal, sovereign, and omnipotent.
(Revelation 21:6)"And he said to me, It is done! I am the Alpha and the Omega, the beginning and the end. To the thirsty I will give from the spring of the water of life without payment." (ESV)
Here we have God the Father saying I am the Alpha and the Omega just like God the Son in Revelation 1:8. God is beyond history, he is eternal.
(Revelation 22:13)"I am the Alpha and the Omega, the first and the last, the beginning and the end." (ESV)
Here we have Jesus as the Alpha and the Omega just like God the Father in Revelation 21:6. Jesus is the "first and the last" just like Yahweh, the only God in Isaiah 44:6 (see also Revelation 1:17).
Also in Revelation 5:13-14 both the Father and Son are worshiped. Only God is worthy of worship. The Book of Revelation clearly teaches that Jesus is God, co-equal and co-eternal with God the Father.